This code return slow and with different output:

from numba import jit
from timeit import default_timer as timer
def fibonacci(n):
    a, b = 1, 1
    for i in range(n):
        a, b = a+b, a
    return a
fibonacci_jit = jit(fibonacci)

let start the test

start = timer()
print fibonacci(100)
duration = timer() - start

let start the test

startnext = timer()
print fibonacci_jit(100)
durationnext = timer() - startnext


print(duration, durationnext)

The result:

C:\Python27>python numba_test_003.py
927372692193078999176
1445263496
(0.00038264393810854576, 0.17378674127528523)

#next

C:\Python27>python numba_test_003.py
927372692193078999176
1445263496
(0.0004830358514597401, 0.19266426987655644)